gpio: init pin after export

This will fully initialize the pin.
The problem is that edge attribute cannot be modified without explicitly
defining pin's direction after boot.
It seems like a kernel issue. This is just a workaround.

Change-Id: I6c9a2c8d20757c3f9d04779a820015c839b8ea5c
Signed-off-by: Konrad Kuchciak <k.kuchciak@samsung.com>

diff --git a/src/interface/peripheral_interface_gpio.c b/src/interface/peripheral_interface_gpio.c
index c1e966f..ce9be7f 100644 (file)
--- a/src/interface/peripheral_interface_gpio.c
+++ b/src/interface/peripheral_interface_gpio.c
@@ -37,6 +37,15 @@ int peripheral_interface_gpio_set_initial_direction_into_handle(peripheral_gpio_
                if (!strncmp(gpio_buf, types[index].type, types[index].len)) {
                        // PERIPHERAL_GPIO_DIRECTION_OUT_INITIALLY_HIGH and PERIPHERAL_GPIO_DIRECTION_OUT_INITIALLY_LOW : out type
                        gpio->direction = (peripheral_gpio_direction_e)index;
+
+                       /*
+                        * Also write to direction for the very first time after boot
+                        * to ensure that the pin is fully initialized.
+                        * Without this, writing to 'edge' is not possible.
+                        */
+                       ret = write(gpio->fd_direction, types[index].type, types[index].len);
+                       CHECK_ERROR(ret != types[index].len);
+
                        return PERIPHERAL_ERROR_NONE;
                }
        }